This invention has to do with the art of refrigerant charged refrigeration; refrigerated air conditioning equipment and is particularly concerned with a novel, light weight, portable refrigerant recovery system and apparatus.
It has become common practice to install or otherwise equip industrial, commercial and dwelling buildings with air-conditioning machines that serve to chill or lower the temperature of air within the buildings and to maintain it at desired comfort levels.
The overwhelming majority of air-conditioning machines are charged with refrigerants, such as FREON, include refrigerant evaporator coils about which air is to be chilled is circulated by means of blowers or fans. The machines further include electric motor-driven compressor pumps that receive and compress gaseous refrigerant existing the evaporator coils; condenser coils receiving the compressed refrigerants from the pumps and which serve to cool and condense the refrigerants into a liquid state. The liquid refrigerants flowing from the condenser coils are conducted into holding tanks or equivalents thereof. The cooled pressurized liquid refrigerants in the holding tanks are conducted through flow-metering expansion valves or equivalent means and vents into the inlet ends of the expansion coils where it expands and absorbs heat from the coils, chilling the coils. The chilled coils absorb heat from the air flowing across their exteriors.
In addition to the above machines of the character referred to above include various censors, monitoring and control means that work to make the machines perform their intended functions in prescribed ways.
The great majority of the classes of machines described above include; pump and condenser coil units that are suitably mounted at the exteriors of their related buildings and expansion coil units that are suitably mounted within their related buildings. In other instances the condensing and expansion coil units are suitably incased and mounted within window openings or the like in their related buildings.
Machines of the nature and character set forth above require periodic or seasonal maintenance servicing and often require that parts thereof be repaired and/or replaced. When being serviced and/or repaired it is not infrequent that the charge of refrigerant in the machines be removed and that the machines be recharged with new or fresh refrigerant when put back into service.
It has been determined that refrigerants such as FREON produced by Dupont, if let to escape freely into the atmosphere, work adverse affects on the atmosphere. Accordingly, strictly enforced laws require that those servicing and working on air-conditioning machines and, the alike prevent the escape of refrigerant into the atmosphere. To this end when it is necessary that the refrigerant be removed from a machine, a drain line is connected to the machine where gaseous refrigerant occurs. The drain line extends to a motor driven gas compressing "recovery pump". The recovery pump receives the gaseous refrigerant, compresses it and delivers it through an elongate cooling line in which it condenses and flows into a refrigerant recovery tank. It is to be noted that the pumps for refrigeration machines and recovery pumps are, most often, piston pumps with popet or reed valves that are made to receive and compress gaseous refrigerants. If liquid refrigerants are let to enter the intakes of those pumps, the pumps hydraulically "lock-up" and cease to function. When such pumps are caused to lock-up, it is not infrequent that they are irreparably damaged. Accordingly, when recovery pumps are used to remove refrigerants from refrigeration machines it is necessary to connect those pumps to portions of the machines where only gaseous refrigerants can be recovered. Accordingly, during the removal of refrigerants from refrigeration machines in accordance with old practices, the liquid refrigerants in the machines must be let to "boil off" to a gaseous state and rise in the machines before it can withdraw from them by the recovery pumps. Boiling off of liquid refrigerants as noted above is a slow and time-consuming process. Further, during the process of letting liquid refrigerant boil off in refrigeration machines the gaseous refrigerants separate from all of the solids and less volatile materials carried thereby and those materials are let to settle and collect in the machines. Accordingly, substantial amounts of undesirable and/or harmful impurities are left in the machines and immediately contaminate new or fresh refrigerants that are introduced into the machines.
It is believed apparent that if the refrigerants in the lower portions of refrigeration machines is extracted there from in a liquid state the solids and other impurities suspended therein and/or carried thereby are extracted or the refrigerants and negligible amounts of impurities are let to remain in the machines to contaminate fresh refrigerants introduced into them.
The refrigerant recovery tanks that are commonly employed when draining refrigeration machines are those common refrigerant supply tanks provided by the manufacturers and distributors of refrigerants. It is common practice for the service and repairmen to return the tanks filled with waste or dirty refrigerants to their refrigerant suppliers for disposal and/or handling. Since the refrigerants are expensive commodities, most suppliers and distributors of refrigerants give the service and repairmen credit for the refrigerants returned to them. That credit is usually applied to the servicemen's next purchases of refrigerants.
Waste refrigerants collected by suppliers and the like are commonly processed to original or new state and put back into circulation in the industry.
It is to be noted that the compressor pumps in the refrigeration machines are lubricated with oils that absorb and carry water and that become laded with acids when put to their intended use. The acids adversely work upon the parts of the machines and upon the refrigerants. As a result of the foregoing, refrigerants in machines become diluted and laded with acid and waste materials.
In an effort to slow the generation of acids and their harmful effects, most refrigeration machines are equipped with small, cartridge-like water and oil absorbing and/or separating devices containing acid neutralizing on base materials. Those devices are short lived and must be frequently replaced. Unfortunately, in the majority of instances the owners of such machines fail to have their machines serviced in a timely manner and do not call for service until they experience or note that their machines (often due to acid-related damage) are no longer functioning as they should function.
It has long been recognized by those in the art that a great deal of the time and costs that are expended in servicing refrigeration machines would be saved if there was a small, compact, and portable means that could be taken to a job site and that would work to remove or drain refrigerant from a machine in a short and reasonable period of time and that would work to clean the refrigerant of solids, acids, water and oil for safe and effective reintroduction of the refrigerant into the machine being serviced.
It is my understanding that unsuccessful efforts to provide means of the character referred to above have been made by others. Those efforts have resulted in systems and apparatus that are too large, too heavy, too complicated and/or too costly to gain acceptance in the art.